Electrical contact attachment

ABSTRACT

An electrical contact unit for attachment to an electromagnetically operated switch comprising a housing divided into two parts each having depending therefrom a leg with a hooked end for engagement of the contact unit with a complementary formation on the switch. The two housing parts are held together by resilient coupling means permitting partial separation of the housing parts against the resilience of the coupling means whereby the contact unit is snap-engageable with the complementary formation on the switch. The contact unit includes relatively movable contact members which are operated by an operating member which couples with an operating member in the switch.

United StatestPatent 11 .1

2/1972 Kane.....-. 335/132 Hayward Dec. 17, 1974 {541 ELECTRICAL CONTACT ATTACHMENT 3,648,203 3/1972 Kane 335/132 [75,], Inventor: William Herbert Hayward, Bedford. 3,676,628 7/1972 Kane 200/280 England Primary Examiner-G. Harris [73] Assignee: Cutler-Hammer, Inc., Milwaukee, Attorney, Agent, 0r Firm--H. R. Rather; Wm. A. Wis. Autio 1 22 F1 d: A 11 1974 1 pr 57 I ABSTRACT -[21] App! 4 An electrical contact unit for attachment to an elec- 3 f tromagnetically operated switch comprising a housing -[30] Foreign Application Priority Data divided into two parts each having depending there- 7 Apr. 18 1973 Great Britain-t... 18839/73 from a legwithv a hooked end for engagement of the contact unit withla complementary formation on the 52 us. c1 335/132, 335/197, 200/280, Switch The w hottsihgPatts are held together by 1 200/303 silient coupling'means permitting partial separation of 51- Int. Cl. H0lh 67/02 the housing PttttS against the resilience of the Coupling [581' Field of Search 335/197, 132-200/280, means whereby Contact is P- 200/303 with the complementary 'formation on the switch. The 1 contact unit includes relatively movable contact mem- [56] k'eferenceslcited bers which are operated by an operating member UNITED STATES PATENTS which couples with an operating member .in the switch. 3.444.345 5/l969 Mackiewicz 200/303 X 5 3.639.866 6 Claims, 5 Drawing Figures after engagement.

1 ELECTRICAL CONTACT ATTACHMENT attachment to a contactor or other electromagnetically operated switch. Sucha contact unit can be used for switching indicator or control apparatus, for example to provide an electrical interlock between two contactors.

Contact units are known which are snap-engageable with the electromagnetically operated switch. These contact units suffer from various disadvantages as regards ease of assembly, ease of snap-engagement with the switch and reliably'secure attachment to the switch An object of the present invention is to provide a contact unit which is free of these disadvantages.

SUMMARY OF THE-INVENTION contact unit with a complementaryflformation on the switch, the two housing parts being held together by resilient coupling means permitting partial separation of The housing encloses a normally open pair of contact members, provided ,by stationary contact members 6, and a normally closed pair of contact members, provided by stationary contact members 7. Respective bridging contact members 8 are carried by an operating member-9 and biased towards the respective stationary contacts by springs 11. The stationary contact members 6 and 7 are securedon the housing by respective terminal screws and conductor clamps shown at 12, which also provide terminals for reception of lead conductors (not shown). The operating member 9 is located .by the two housing parts 1, is slidable up and down (as shown in FIGS. 2 and 3) and is engageable at the two housing parts against the resilience of said coupling means whereby the contact unit is snapengageable with said. complementary formation, relatively movable contact members in the housing and an operating member for said contact members.

' BRIEF DESCRIPTION OFTHE DRAWINGS FIGS. 3, 4 and 5 are sectional viewson the lines AA, 8-8 and C-C respectively.

Referring to the drawings, there is shown an electrical. contact unit 10 for attachment to an electromagnetically operated switch 20, and FIG. 3 shows the contact unit actually attached to such a switch. The contact unit 10 comprises a housing dividedinto two identical parts 1, held together by a resilient coupling means or coupling 2, 3, 4. Specifically,'a flat head pin 2, of a kind commonly used for rivetting, passes through apertures la in the two housing parts andthe free end of the pin is secured by a push fitting resilient clip 3 of the kind commonly known as a spire clip. A similar but larger sized clip 4 is provided between the head of the pin 2 and the adjacent housing part 1 to provide resilience in the coupling of thetwo parts and is chosen too large to grip the stem of the pin. The clip 4 may be replaced by a leaf or helical spring. The resilient coupling permits partial separation of the two housing parts 1 against the resilience of the clip 4.

' Each housing part is formed with two depending legs 5 each formed with a hooked end for engagement of the contact unit with a complementary formation 22 on the switch 20. Because the resilient coupling of the two housing parts permits partial separation thereof, the

its lower end with a slidable operating member 24 in the switch 20, for example as shown by means of a keyhole on the switch operating member 24 and in interlocking key on the operating member 9 of the contact unit.vv I, I

' To assemble the contact unit, the two parts 1 of the housing, with the stationary contacts 6 and 7 mounted thereon, are first assembled round the contact unit operating member 9. The pin 2, with the resilient element 4 on it, is then inserted through the two parts 1 and the clip 3 pushed on to the free end of the pin 2 to secure the housing parts together. The contact unit is'then clippedonto the switch 20, the opeating member 9 of the contact unit being connected to the switch operating member 24, and the depending legs 5 on the housing parts 1 snap-engaging the complementary formation 22 on the switch, the clip 4 providing the necessary resilience.

I claim:

1. An electrical contact unit for attachment to an electromagnetically operated switch, said contact unit comprising: i

a. a housing divided into parts;

b. at least one leg dependingv from each housing part;

which said resilientmeans comprises:

a. an elongate member;

b. an abutment on said elongate member; and

c. a spring acting between said abutment and one housing part to hold said elongate member under tension.

3. An electrical contact unit as claimed in claim 1, comprising means in which said operating member is mounted for reciprocal sliding movement in the direction of snap-engagement of the contact unit with said complementary formation. a

4. An electrical contact unit as claimed in claim 3, comprising means formed on said operating member and engageable with an operating member in said switch.

5. An electrical contact unit as claimed in claim 1, comprising at least one pair of contact members and a bridging contact member for bridging said pair of contact members.

6. An electrical contact unit as claimed in claim 1, in

which the two housing parts are identical. 

1. An electrical contact unit for attachment to an electromagnetically operated switch, said contact unit comprising: a. a housing divided into parts; b. at least one leg depending from each housing part; c. a hooked end formed on each leg, for engagement of the contact unit with a complementary formation on the switch; d. resilient means holding the two housing parts together and permitting partial separation of the two housing parts against the resilience of said means whereby the contact unit is snapengageable with said complementary formation; e. relatively movable contact members in the housing; and f. an operating member for said contact members.
 2. An electrical contact unit as claimed in claim 1, in which said resilient means comprises: a. an elongate member; b. an abutment on said elongate member; and c. a spring acting between said abutment and one housing part to hold said elongate member under tension.
 3. An electrical contact unit as claimed in claim 1, comprising means in which said operating member is mounted for reciprocal sliding movement in the direction of snap-engagement of the contact unit with said complementary formation.
 4. An electrical contact unit as claimed in claim 3, comprising means formed on said operating member and engageable with an operating member in said switch.
 5. An electrical contact unit as claimed in claim 1, comprising at least one pair of contact members and a bridging contact member for bridging said pair of contact members.
 6. An electrical contact unit as claimed in claim 1, in which the two housing parts are identical. 